Angular‐Shaped 4,9‐Dialkyl α‐ and β‐Naphthodithiophene‐Based Donor–Acceptor Copolymers: Investigation of Isomeric Structural Effects on Molecular Properties and Performance of Field‐Effect Transistors and Photovoltaics

Two angular‐shaped 4,9‐didodecyl α‐aNDT and 4,9‐didodecyl β‐aNDT isomeric structures have been regiospecifically designed and synthesized. The distannylated α‐aNDT and β‐aNDT monomers are copolymerized with the Br‐DTNT monomer by the Stille coupling to furnish two isomeric copolymers, PαNDTDTNT and PβNDTDTNT, respectively. The geometric shape and coplanarity of the isomeric α‐aNDT and β‐aNDT segments in the polymers play a decisive role in determining their macroscopic device performance. Theoretical calculations show that PαNDTDTNT possesses more linear polymeric backbone and higher coplanarity than PβNDTDTNT. The less curved conjugated main chain facilitates stronger intermolecular π–π interactions, resulting in more redshifted absorption spectra of PαNDTDTNT in both solution and thin film compared to the PβNDTDTNT counterpart. 2D wide‐angle X‐ray diffraction analysis reveals that PαNDTDTNT has more ordered π‐stacking and lamellar stacking than PβNDTDTNT as a result of the lesser curvature of the PαNDTDTNT backbone. Consistently, PαNDTDTNT exhibits a greater field effect transistor hole mobility of 0.214 cm² V^?1 s^?1 than PβNDTDTNT with a mobility of 0.038 cm² V^?1 s^?1. More significantly, the solar cell device incorporating the PαNDTDTNT:PC₇₁BM blend delivers a superior power conversion efficiency (PCE) of 8.01% that outperforms the PβNDTDTNT:PC₇₁BM‐based device with a moderate PCE of 3.6%.     

Geometric error calibration of multi-axis machines using an auto-alignment laser interferometer

This work will report the development and application of an auto-alignment laser interferometer system for the geometric error calibration of CNC multi-axis machines. The system is capable of a diagonal displacement measurement, where multiple machine axes are moved simultaneously, with automatic optic alignment. This capability provides a solution for quick evaluation of the overall volumetric error of a multi-axis machine tool. One application of the system is that the 21 geometric errors of a 3-axis machine can be quickly estimated from the displacement measurements of some determined diagonal lines in the working volume. Compared with a time of several days using a conventional laser interferometer system, it takes only 1 hour for the proposed system to complete the geometry calibration of a 3-axis machine. A method for the roll calibration of a vertical axis is also proposed and demonstrated in this work.     

Synthetic routes and lipase-inhibiting activity of long-chain α-keto amides

Synthetic routes to primary and N-alkyl α-keto amides are presented in this paper. Primary α-keto amides may be prepared by using an aldehyde as starting material. Commercially available α-keto acids may be coupled in high yield with primary amines by the mixed carbonic anhydride method affording N-alkyl α-keto amides. Alternatively, N-alkyl α-keto amides may be prepared by coupling long-chain α-hydroxy acids with amino components, followed by oxidation with pyridinium dichromate or NaOCl in the presence of 4-acetamido-2,2,6,6-tetramethyl-1-piperidinyloxy free radical. The α-keto amide derivatives prepared according to these procedures were tested for their ability to form stable monomolecular films at the air/water interface. The inhibition of porcine pancreatic lipase by the α-keto amides, spread as mixed films with 1,2-dicaprin, was studied with the monolayet technique. Among the compounds tested in this study, methyl 2-[(2-ketododecanoyl)aminol]hexadecanoate was shown to be the most potent inhibitor, causing a 50% decrease in lipase activity at a 0.09 molar fraction.     

Antioxidant,Anti-Tyrosinase and Anti-Inflammatory Activities of Oil Production Residues from Camellia tenuifloria

Camellia tenuifloria is an indigenous Camellia species used for the production of camellia oil in Taiwan. This study investigated for the first time the potential antioxidant, anti-tyrosinase and anti-inflammatory activities of oil production byproducts, specifically those of the fruit shell, seed shell, and seed pomace from C. tenuifloria. It was found that the crude ethanol extract of the seed shell had the strongest DPPH scavenging and mushroom tyrosinase inhibitory activities, followed by the fruit shell, while seed pomace was the weakest. The IC₅₀ values of crude extracts and fractions on monophenolase were smaller than diphenolase. The phenolic-rich methanol fraction of seed shell (SM) reduced nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) expression in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. It also repressed the expression of IL-1β, and secretion of prostaglandin E₂ (PGE₂) and IL-6 in response to LPS. SM strongly stimulated heme oxygenase 1 (HO-1) expression and addition of zinc protoporphyrin (ZnPP), a HO-1 competitive inhibitor, reversed the inhibition of NO production, indicating the involvement of HO-1 in its anti-inflammatory activity. The effects observed in this study provide evidence for the reuse of residues from C. tenuifloria in the food additive, medicine and cosmetic industries.     

Remote research methods for Human–AI–Robot Teaming

This study focuses on methodological adaptations and considerations for remote research on Human–AI–Robot Teaming (HART) amidst the COVID-19 pandemic. Themes and effective remote research methods were explored. Central issues in remote research were identified, such as challenges in attending to participants' experiences, coordinating experimenter teams remotely, and protecting privacy and confidentiality. Instances of experimental design overcoming these challenges were identified in methods for recruitment and onboarding, training, team task scenarios, and measurement. Three case studies are presented in which interactive in-person testbeds for HART were rapidly redesigned to function remotely. Although COVID-19 may have temporarily constrained experimental design, future HART studies may adopt remote research methods to expand the research toolkit.     

The Anti-Cancer Effects of a Zotarolimus and 5-Fluorouracil Combination Treatment on A549 Cell-Derived Tumors in BALB/c Nude Mice

Zotarolimus is a semi-synthetic derivative of rapamycin and a novel immunosuppressive agent used to prevent graft rejection. The pharmacological pathway of zotarolimus restricts the kinase activity of the mammalian target of rapamycin (mTOR), which potentially leads to reductions in cell division, cell growth, cell proliferation, and inflammation. These pathways have a critical influence on tumorigenesis. This study aims to examine the anti-tumor effect of zotarolimus or zotarolimus combined with 5-fluorouracil (5-FU) on A549 human lung adenocarcinoma cell line implanted in BALB/c nude mice by estimating tumor growth, apoptosis expression, inflammation, and metastasis. We established A549 xenografts in nude mice, following which we randomly divided the mice into four groups: control, 5-FU (100 mg/kg/week), zotarolimus (2 mg/kg/day), and zotarolimus combined with 5-FU. Compared the results with those for control mice, we found that mice treated with zotarolimus or zotarolimus combined with 5-FU retarded tumor growth; increased tumor apoptosis through the enhanced expression of cleaved caspase 3 and extracellular signal-regulated kinase (ERK) phosphorylation; decreased inflammation cytokines levels (e.g., IL-1β, TNF-α, and IL-6); reduced inflammation-related factors such as cyclooxygenase-2 (COX-2) protein and nuclear factor-κB (NF-κB) mRNA; enhanced anti-inflammation-related factors including IL-10 and inhibitor of NF-κB kinase α (IκBα) mRNA; and inhibited metastasis-related factors such as transforming growth factor β (TGF-β), CD44, epidermal growth factor receptor (EGFR), and vascular endothelial growth factor (VEGF). Notably, mice treated with zotarolimus combined with 5-FU had significantly retarded tumor growth, reduced tumor size, and increased tumor inhibition compared with the groups of mice treated with 5-FU or zotarolimus alone. The in vivo study confirmed that zotarolimus or zotarolimus combined with 5-FU could retard lung adenocarcinoma growth and inhibit tumorigenesis. Zotarolimus and 5-FU were found to have an obvious synergistic tumor-inhibiting effect on lung adenocarcinoma. Therefore, both zotarolimus alone and zotarolimus combined with 5-FU may be potential anti-tumor agents for treatment of human lung adenocarcinoma.     

Improving thin-film crystalline silicon solar cell efficiency with back surface field layer and blaze diffractive grating

Both 2D electromagnetic and electrical semiconductor simulations are performed sequentially in this study in order to better understand the structural principles of thin-film crystalline solar cells with back surface field and blaze diffractive grating. In the absence of adequate approximations for blazed gratings, we simulate silicon solar cells electromagnetically and electrically in order to deal with the geometrical complexity produced by the blazed grating with a BSF on top of it. Thin-film crystalline silicon solar cells (TF-c-Si SCs) typically exhibit poor quantum efficiency both at shorter wavelengths and longer wavelengths with sharp drops in spectral response. Longer wavelength spectral response (from 0.6 μm to 1.2 μm) is addressed here first by considering the influence of blaze gratings on the enhancement of effective optical absorption in thin-film crystalline silicon (TF-c-Si) solar cells. The effect of the back surface field layer (BSF) in terms of improving minority carrier collection is also taken into account. In the 2D electromagnetic simulation, polarization dependent two-dimensional (2D) numerical simulations based on rigorous coupled wave analysis (RCWA) and finite element method (FEM) are implemented for the optimization of optical absorption of the solar cell structure. A rather large tolerance in design parameters of the optimized blaze grating structure was found. The optimized blaze grating structures help in improving the cell efficiency, especially for weak absorption thin cell structures. The enhancement of equivalent optical path length reveals the efficient light trapping effect caused by the diffractions of the blaze grating structures, especially in the longer wavelength range. In the electrical semiconductor simulation, the BSF, which arises from the heavy acceptor doping that creates the concentration gradient, is set atop the blaze grating in order to provide an extra small drift field for the collection of minority electrons. Incorporating the optimized antireflection coating along with a BSF layer and a blaze-grating in the 2 μm cell doubles cell efficiency. The use of blazed gratings in thin-film solar cells, which can be performed upon silicon by means of lithography and ion-beam etching, is promising for low cost and high-efficient solar cell applications.     

Mesoporous platinum nanosponges as electrocatalysts for the oxygen reduction reaction in an acidic electrolyte

Mesoporous Pt nanosponges of high activity were successfully synthesized for the oxygen reduction reaction (ORR). These porous nanosponges of 48.7, 53.7, 62.8, and 77 nm in size were synthesized by changing the concentration of polyvinylpyrrolidone electrolyte in the electrochemical synthesis. The electrochemically active surface areas (EASs) of the 48.7-, 53.7-, 62.8-, and 77-nm Pt nanosponges used toward H-adsorption and H-desorption were 162.84, 137.76, 116.71, and 103.83 m²/g, respectively. These measured EASs of these nanosponges were larger than the EAS contributed by the Pt nanoparticles of 76.69 m²/g. As for the ORR, electrochemical measurement and Koutecky-Levich plots showed that the kinetic current densities catalyzed by the 48.7-, 53.7-, 62.8-, and 77-nm Pt nanosponges at 0.7 V (vs. Ag/AgCl) were 0.488, 0.483, 0.450, and 0.370 mA cm⁻², respectively; and the 48.7-nm Pt nanosponges had high reducing activity in the ORR. A size-dependent activity was found. As a reveal of the results of a rotating ring-disk electrode experiment, the catalysis of the ORR by the 48.7-nm Pt nanosponges occurred through the 4-electron pathway, and the efficiency of H₂O production was approximately 99.4%.